International NamesSonic Underground (Original English), Sonic Le Rebelle (French)
When Sonic was getting ready for a big come back which turned out to be Sonic Adventure, Some people at DIC wanted to bring a cartoon show back. They got together number of writers, these mostly seam to be people that worked on 'Sonic the Hedgehog' and 'Adventures of Sonic the Hedgehog' and showed them an episode of 'Sonic the Hedgehog' and stated that they wanted a show like this one. Work went on for the show and, maybe due to the writers, it took on a mixture of Adventures with SatAM. Jaleel White was brought back to play the role of Sonic, but on top of this, he had a chance to show of his skills by also doing the newly created Sonia and Manic, Sonic's Lost lost sister and Brother. While many disagreed with this idea, there isn't really anything that goes directly against it, per say, in fact the show made itself in such a way that, with only a little bit of changing, the earlier 'Sonic the Hedgehog' show could in fact fit into it's story arc. Very little seams to be known about the early days of the shows creation but there is a lot visible as the show goes on.
Quite early on, the basic ideas seams to have been set up. At the time, TV shows featuring bands were making a come back after they went away near the start of the 90s (Shows featuring groups like Alvin and the Chipmunks & California Raisins were part of this era, and shows like 'Super Mario Brothers', featured a Song in each episode, much like the style of the others at the time). During the Comeback, the era was mostly filled by live action shows such as "Cleopatra: Comin' Atcha" (The second series was subtitled 'In the house instead of 'Comin' Atcha) featuring the girl band 'Cleopatra', "STARStreet*", featuring band 'allSTARS*' & "Miami 7", featuring band 'SClub 7'. To match in with the new age of Musical shows, Sonic and his two siblings were given the role of being in a band. Sonic has already shown playing on a guitar in both AOSTH and SatAM (but not often at all) and he took up the guitar again, his Sister Sonia was given a Keyboard, and Brother Manic was given a Drum kit. To allow them to carry their kit around and, unlike other shows where it would just turn up or the Songs wouldn't be part of the story, the band's instruments were given a 'magic' twist in that they turned into medallions they wore around there neck and could call on them at will.
The show clearly had more money per episode then 'Adventures of Sonic the hedgehog', but less then 'Sonic the Hedgehog', part of this is noticeable via the 40 episodes. While the show seamed to very much follow the Syndication idea, there are a lot more story lines that carry on in some way (and two 3 part stories, officially mixed up together). As the show goes along, it seams very noticeable all the changes. Jaleel White gets better at doing the three voices and, unlike first episodes (which seams to be a pilot), the voices become very much the same each time he speaks. In that first episode 'Wedding Bell Blues', in the opening scene, Sonic, Manic and Sonia's voices do seam to change a little from line to line, and Manic's first line sounds nothing like him later on. But things get better pretty quickly and he seams to really fit into the roles pretty well.
Many cast members return from previous Series, such as Jaleel White as Sonic, Sonia and Manic, Gary Chalk, now as Dr Robotnik, Ian James Corlett as Knuckles and Cyrus with Matt Hill as Trevor, Gail Webster as Queen Aleena, Maurice LaMarche (Futurama, Pinky and the Brain, Tiny Toon Adventures, The Real Ghost Busters, and Many more) as Sleet and Peter Wilds as Dingo. This was the final Sonic Cartoon and in fact, it marked the full end of the Classic Sonic Period.